For such refuge chambers/safety rooms, it is known that they need a cooling system if people stay in the interior thereof. An air conditioning system, or the like, is considered for the cooling system. However, only an operation of special, so-called explosion-proof air conditioning systems is permissible in potentially explosive areas. Usually, electrical air conditioning systems are ruled out for such a use because electrical discharges or electrical arcings may ignite ignitable mixtures (for example, methane, coal dust, etc.) and trigger explosions.
A refuge chamber with a means for cooling and dehumidifying the interior of the refuge chamber has become known from CN 201 857 993 U. The achieving of the cooling action is based here on the use of compressed liquid carbon dioxide (CO2). The liquid carbon dioxide is provided in the compressed form in containers provided for this and is supplied via a pressure reducer, on the one hand, to a vortex tube for cooling and, on the other hand, to a pneumatic motor for driving a fan. In addition, the ambient heat taken up during the driving of the pneumatic motor with carbon dioxide as well as an air stream generated with a drive of a fan by the pneumatic motor shall be used for cooling the interior of the refuge chamber as well. The pneumatic motor is combined with, among other things, a radiator into an air dehumidifying and air purifying unit. Corresponding chemicals, which are placed in the air stream arising because of the fan by means of the air dehumidifying and air purifying unit, are provided for absorbing carbon dioxide (CO2) and carbon monoxide (CO) in the ambient air in the interior of the refuge chamber.
A refuge chamber for use in mining, comprising a cooling means, which can be put into operation only at a methane concentration below a predetermined level within the refuge chamber, is known in U.S. Pat. No. 8,007,047 B2.
A personal safety system in the form of a refuge chamber with a security entrance, a holding room connected to the security entrance and with an air curtain device on the entrance door of the security entrance, is known from the not previously published DE 10 2011 014 104 of Mar. 28, 2011. So that persons can reach the holding room in a short time, a circulating air system is provided for the interior of the refuge chamber. Besides the holding room, the interior includes the security entrance as well. The circulating air system comprises an air feed means and a toxic gas filter, an air flushing means comprising air cells for the holding room as well as a gas supply duct for respirator products in the holding room.